Thread-case tension



July 14, 1925.

1,546,029 L. SCHILDKNECHT THREAD CASE TENSION Filed Feb. 4, 1922 In ve n"207' Leo Sch z'Zdknech-Z' Patented July 14, 1925 UNITED STATES PATENTOFFICE.

LEO SCI-IILDKNECH'I, OF ST. LOUIS, IJIESOURI, ASSIGN' OR TO LANDISMACHINE GOM- PANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

THREAD-CASE TENSION.

Application filed February 4, 1922 Serial vNo. 534,215.

To all whom it may concern:

Be it known that I, LEO SG-HILDKNEOHT, a citizen of the United States,residing at St. Louis, Missouri, have invented a certain new and usefulImprovement in Thread-Case Tensions, of which the following is a full,clear, and exact description, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto-the accompanying drawings, forming part of this application. I

My invention relates to thread cases such as are used in shoe sewingmachines for containing a thread bobbin and consists in an improvedthread tension device for such cases.

The object of my invention is to provide an eflicient adjustable tensiondevice low in cost and easily adjusted.

In the accompanying drawings which illustrate a preferred form of myinvention,

Figure 1 is a top view of a thread case to which my invention isapplied.

Figure 2 is an edge view of the thread case showing my tension device.

Figure 3 is another edge view of the case taken at right angles toFigure 2.

Figure 4 is a section on line 4-4 of F igure 2.

The thread case 1 is shaped like a shallow cup and is of a form incommon use and needs no particular description as to its construction oroperation. It is provided with a peripheral groove 2 extending part ofthe way around the case and having a depth approximating a half of thethickness of the case wall. An integral finger 3 extends upwardly andoutwardly from the case. A thread opening 4 extends from groove 2through finger3 and spaced a short distance from opening 4 is a secondthread opening 4- connecting the interior of the case with groove 2.

Positioned in groove 2 is an arcuate thread engaging member 5,preferably made of spring steel, and fixedly secured by rivets orotherwise at one end 6 to the wall of the case. Near the unfixed end ofmember 5 the member is bent downwardly and upwardly as at 7 to permitunobstructed passage of a thread through the case Wall and to engage thethread as at 8 and to press same against the upper edge of groove 2.

To control the pressure of member 5 on the thread, I provide :a cam 9,pivotally mounted in a recess 10, which is located in the edge of thecase and intersects groove 2. Gain 9 is preferably polygonal throughoutthe larger portion of its perimeter, the successive sides being spacedat increasing distances from the center of the cam. One portion of thecams periphery is provided with extending tongues 11 spaced from eachother to permit the insertion of a knife blade or other tool to turn thecam on its pivot to bring various edges of the cam in contact withmember 5. It is obvious that by means of the cam the space between theupper edge of member 5 and the top edge of groove 2 may be varied toaccommodate different sizes of threads and different tensions required.Due to the polygonal construction of the cam, any adjustment made willbe positively retained so that no additional means are required forholding the cam in any adjusted position.

As previously mentioned member 5 is preferably of spring material and isset so that it tends to press against cam 9; consequently there willalways be the maximum opening at 8, which the cam will permit. Theeccentric is spaced a substantial distance from the unfixed end ofmember 5 so as to permit a yielding engagement of the thread by this endof the tension member.

The above described tension device is comparatively easy and economicalto manufacture, is readily adjustable, and positive in its action. Theinvention embodied is capable of being applied in various forms and Icontemplate all such modifications as fall within the scope of thefollowing claims.

I claim:

1. In combination, a circular thread case having a peripheral groovewith a thread engaging surface, a friction member in said groove havinga thread engaging surface at one end opposed to said groove surface, apivot fixed on said case, and a cam journaled on said pivot and engagingsaid member at a point between its ends spaced substantially from itsthread engaging surface.

2. In combination, a circular thread case having a peripheral groovewith a thread engaging surface, a friction member in said groove havinga thread engaging surface opposing said case surface, and a polygonalcam pivoted at a fixed point on the side of said case having straightfaces for engaging said movable bearing element located at difierentdistances from its pivot whereby rotation of said cam adjusts saidmovable bearing element relative to said fixed bearing element.

3. In a circular thread case having a peripheral groove and threadopenings leading to and from said groove, a member in said grooveadapted to oppose one edge of the groove to frictionally engage a threadpassed through said openings, and a cam sunk in the periphery of saidcase and movable on an axis extending radially of the case with its edgehaving adjusting contact with said member.

4. In a circular thread case having a peripheral groove an arcuatethread engaging member located in said groove and having one end fixedto said case and its other end movable across said groove to adjust thespace between one side of the member and the side of the groove, arecess in the periphery of said case adjacent said groove, a polygonalcam pivoted in said recess on an axis extending radially of the cam andprojecting into said groove and engaging the opposite side of saidmember near its movable end.

In testimony whereof I hereunto afiix my signature this 31st day ofJanuary, 1922.

LEO SOHILDKNECHT.

